Dental material and method



June 26, '1951 R. s. JOHNSON CRANBERRY WASHER 2 Sheets-Sheet 2 Filed Dec. 10, 1948 INVENTOR. R0551? T S. (/OHNSON HTTOR/VFVS Patented June 26, 1951 c c r 2,558,138

UNITED STATES PATENT OFFICE CRANBERRY WASHER Robert S. Johnson, Plymouth, Mass. Application December 10, 1948, Serial No. 64,689

4 Claims.

1 My invention relates to washers for cranberries, and more particularly to a device for washing cranberries which are harvested by flooding a cranberry bog and scooping up the floating cranberries from the surface of the flood water. As is well known, after a cranberry bog has been picked, a number of the berries are still available on the ground. Such berries are usually harvested by flooding the bog and thereafter scooping up the floating berries. However, cranberries thus harvested are intermixed with other floating debris, such as small sticks, twigs, leaves and the like, where the cleaning of such berries presents a real problem.

With the foregoing in view, it is an object of my invention to provide an improved Washer for cranberries.

A further object is to provide an improved washer for cranberries which comprises a substantially horizontal washing drum comprising a cylindrical wall formed of a plurality of spaced slats, together with means for spray-washing cranberries in said drum and means for rotating the drum during the washing operation.

A further object is to provide in a cranberry washer such as that last described a hopper for introducing cranberries to one end of the drum, and wherein said hopper includes a floor inclined toward the drum and formed of a plurality of spaced slats, together with means for spray- Washing cranberries in said hopper preliminary to their introduction to the drum.

Other objects and advantages reside in the particular structure of the invention, combination and arrangement of the several parts thereof, and will be readily understood by those skilled in the art upon reference to the attached drawings, in connection with the following specification, wherein the invention is shown, de-

scribed and claimed.

In the drawings:

Figure 1 is an elevationalview of the device according to the invention;

Figure 2 is a plan view thereof;

Figure 3 is a longitudinal vertical sectional view taken substantially on the plane of the line 3-3 of Figure 2;

Figure 4 is a transverse vertical sectional view taken substantially on the plane of the line 44 of Figure 2;

Figure 5 is a fragmentary transverse vertical sectional view taken substantially on the plane of the line 5-5 of Figure 2;

Figure 6 is a fragmentary longitudinal vertical sectional view through the frame for the device, parts being omitted.

Referring specifically to the drawings, wherein like reference characters have been used throughout the several views to designate like parts, It designates any suitable base or bed for the device according to the invention. The base It may be of any suitable size, but it is preferred that the device be of such a size as to be readily carried about in a motor truck or the like so as to assure full portability of the invention. Any suitable motor or engine H is mounted at one end of the base or bed It in any suitable manner. In practice, the engine ll preferably comprises an internal combustion engine of any suitable type, but it is to be understood that where a source of electricity is readily available, the engine Il may well comprise an electric motor. The motor or engine ll includes a drive shaft I3 to which is fixed any suitable drive pulley l4 which may be connected by a belt iii to a driven pulley l6 fixed on a driven shaft I? which is journaled in any suitable bearings It, on the frame members i2. The driven shaft ll extends longitudinally of the base or bed It in vertically-spaced relation thereto. Intermediate its ends, the driven shaft IT has fixed thereon a driven pinion [9 which is in constant mesh with a ring gear 20 fixed on a washing drum 2i. It should be noted that the arrangement is such as to comprise a reducing gearing whereby the drum El is rotated at a much slower rate of speed than is the drive shaft is of the motor ll. g

The drum 2i comprises a plurality of slats 22 disposed longitudinally in the form of a cylindrical wall. The slats 22 are preferably in the form of cylindrical rods and are spaced apart a distance less or slightly less than the diameter of a full-sized cranberry. The ring gear 28 encircles the slats 22 intermediate their ends and such slats are seated at one end in a relatively broad ring 23, and at the other end in a relatively narrow ring 24. As best seen in Figures 3 and 5, each frame member l2 has mounted thereon in laterally-spaced and aligned relation a pair of flanged rollers 25 on which the rings 24 and 23 are rotatably seated whereby to rotatably mount the drum 2| between the frame members 12. A plurality of helically-dispcsed, combined agitators and lifts 26 are mounted on the drum 2; interiorly thereof. The arrangement of the lifts and/or agitators 26 is such that as the drum is rotated in the direction of the arrow, Figure 1, cranberries supplied to the righthand end of the drum 21 will pass therethrough from right to left and be delivered from the left-hand end of the drum.

The right-hand end of the drum 2| is supplied with cranberries from a hopper 2'! which is supported in any suitable manner from the righthand frame member l2. The hopper 21 includes a floor comprising a plurality of spaced slats preferably in the form of cylindrical rods which extend longitudinally of the hopper and are downwardly inclined toward the drum 2|. Likewise,

Patented June 26, 1951 DENTAL MATERIAL AND METHOD Frances E. Knock, Oak Park, 11]., and John F. Glenn, Milford, Del., assignors to The L. D. Caulk Company, Milford, Del., a corporation of Delaware No Drawing. Application August 26, 1947,

Serial No. 770,756

14 Claims.

This invention relates to a dental material and method, and more particularly, to an improved material and method for dental restorations including the production of materials which quickly harden in the mouth and are useful for direct filling materials, denture reliners and cements for inlays and jacket crowns and other dental appliances, as well as for the fabrication of appliances made outside the mouth, such as dentures, both temporary and permanent, individual impression trays, denture repairs, dental splints, orthodontia space retainers, bite opening appliances, study models, jacket crowns, base plates, etc.

The dental materials of the present invention, when admixed for use, range from a viscous liquid in the case of dental adhesives to a thick dough for direct filling materials. All of the -materials have a liquid polymerizable monomer content, at least one polymerization catalyst and at least one polymerization promoter and also have the common property hardening to a tough non-porous material by polymerization of the liquid monomer content at low temperatures, i. e., ordinary room temperatures or temperatures no higher than mouth temperatures. Most of the compositions of the present invention also desirably include a finely divided polymer or mixture of polymers which may be at least partly soluble in the monomer employed, although in some instances all or a portion of the polymer content may be substantially insoluble in the monomer so as to function as an inert filler and in certain cases other finely divided inert fillers, such as ground glass, talc, silica, insoluble inorganic salts, solid organic plasticizers, pigments, etc., may be substituted in whole or in part for the polymer. In any event, the essential material in the final product is a polymerized material produced by polymerizing a monomer or mixture of monomers in situ in the presence of a suitable polymerization catalyst and a polymerization promotor. Volatile solvents for any of the materials are preferably omitted.

'Dental material for denture reliners, direct filling materials and dental adhesives containing polymerized material have heretofore frequently contained substantial amounts of volatile organic solvents for the polymer. Hardening of such dental material in situ in the patients mouth has been by reason of evaporation of the volatile solvent or leaching of the solvent from the dental material by the mouth fluids or both. The reof quickly moval of the solvent from the residual solid polymer has caused shrinkage of this material so that it has been 'diflicult or impossible to secure adequate adhesion to the teeth or denture or to accurately produce the desired shapes in the case of fillings or denture reliners. Also, the removal of the solvent has caused the residual solid polymer to develop pronounced porosity which not only detracts from the appearance of the material but results in a rapid collection of foreign organic material in the pores with consequent fouling of the denture or other restoration. Furthermore, in the case of denture reliners, penetration of the volatile solvent into the material of the denture base causes definite weakening of the base.

When fabricating dentures and other dental appliances made outside the mouth the hardening of the denture material has been carried out in molds constructed in accordance with known procedures. The most successful of the previously employed compositions have, however, been slow to harden and have required at least several hours treatment at elevated temperatures to convert the molded material to a hard structurally strong material.

In contrast, the dental materials of the present invention harden by polymerization of a monomer or mixture of monomers into a hard, non-porous, structurally strong material within a short time either in the mouth when subjected to mouth temperatures or for appliances made outside the mouth, when subjected to ordinary room temperatures. In the latter case, moderately elevated temperatures may be employed but are usually not necessary. The rapid hardening is produced by employing a polymerization promoter in addition to a polymerization catalyst. The catalysts employed are either peroxide or persulfate catalysts, or various mixtures thereof. The monomer content can be substantially any monomer or mixture of monomers which have their polymerization reaction catalyzed by such catalysts and the promoter may be any one of a large number of nitrogen containing compounds as hereinafter more specifically discussed.

It is therefore an object of the invention to provide an improved dental material and process for fabricating various dental restorations either in the mouth or exterior thereof.

Another object of the invention is to provide an improved dental material which may range from a viscous liquid to a stiff dough and which hardens at room or mouth temperatures without substantial shrinkage into a non-porous structurally strong material within a short time.

Another object of the invention is to provide a new dental material and process in which a polymerization promoter in addition to a polymerization is employed to produce rapid polymerization and hardening of a monomer or monomer mixture forming part of the dental material.

Other objects and advantages of the invention will appear in the following description of preferred embodiments thereof.

The monomer most frequently employed in the production of dental restorations has been methyl methacrylate because its superior optical properties, dimensional stability, chemical and water resistance and resistance to aging of its polymers and eopolymers and ready availability. The invention will be discussed largely in connection with the polymerization of methyl methacrylate but as will appear below, the present invention renders various other monomers available for dental purposes by eliminating factors which have heretofore restricted their use, for example, their slow polymerization rate. A large number of nitrogen containing compounds promote polymerization of methyl methacrylate, as well as many other monomers containing a vinyl or vinylidene group and also promote copolymerization of various mixtures of such monomers, when employed in conjunction with a peroxide or a persulfate catalyst. In general, nitrogen containing promoters are not polymerization catalysts whenused by themselves or in a mixture with each other and may even inhibit polymerization reactions in the absence of a peroxide or persuliate catalyst. Certain of them may have some catalytic action when employed in the absence of a peroxide or persulfate catalyst, but this effect is usually below that of the catalytic effect of peroxide or persulfate catalysts. When employed in conjunction with a peroxide or persulfate catalyst, however, the promoters of the present invention markedly accelerate or promote polymerization or copolymerization of methyl methacrylate and other monomers or mixtures of monomers of the same general type. That is to say, the reaction is very p-Diethylamino chloro benzene cigar- 0.11.

N-plienyl glycine Trl-isopropanolamine N-(CHg-CH-CHI) tn N-butyl-maleinimide Phthalimlde 0f the above compounds, the first seven are approximately equally active as promoters and markedly decrease the time required for polymuch faster than is the case when the peroxide merization at a given temperature in the presor persulfate are employed in the absence of a promoter.

The most effective nitrogen-containing compounds thus far found which promote polymerization or copolymerization reactions in the presence of a peroxide or persulfate catalyst are:

Meta tolyl diethanolamine CHzCHgOB Phenyl diethanolamine O-N-(CgHoOH):

fl-Hydroxyethyl ethyl aniline C gH fi-Hydroxyethyl methyl aniline Ci A0H p-Diethyl aminodiphenyl maleinimide and phthalimide produce a some-' what slower reaction than the N-phenyl glycine. These compounds are, however, useful even at the lower temperatures referred to and are also useful at higher temperatures.

While the above listed compounds are the most active polymerization promoters tested, there are a large number of nitrogen-containing compounds which do have a substantial promotion activity. Examples of such nitrogen-containing compounds which efiect a somewhat slower reaction when employed as polymerization promoters along with a peroxide or persuliate catalyst, but which are useful for many purposes, are:

Creatinine, diisobutyl nitrosamine, chlorosaccharin, barblturic acid, N-aceto saccharin, thicbarbituric acid, acetanalide, N,N'-dichlorodimethyl hydantoin, N-chloroacetamide, mel- 

